Issues on cascading a Dc/Dc boost converter with an inverter

[Solarnewbies]

Project : Study on Cascade a dc/dc boost converter with an inverter for grid application.

Problem encountered:

1) The i/p voltage of the dc/dc converter is increase gradually ( 0Volt to 30volts) to observe the reliability of the design circuit.


2) When the i/p voltage of the dc/dc boost coverter is increase to above 10V, there will be a sudden huge jump in the i/p current about 2~3 times the normal range. The o/p of the inverter is working fine (voltage & Current)

I have been working on this study for a few months and still unable to know what causes the i/p current to behave abnormal (sudden increase higher than range). Hope that someone pro will able to provide valuable advices. Very much appreciate!

 

[pauloynski]

Re: Issues on cascading a Dc/Dc boost converter with an inve

Seems that the inductor of the boost circit is going into saturation.
Regards

Added after 5 minutes:

https://www.daycounter.com/LabBook/BoostConverter/Boost-Converter-Equations.phtml

 

[Solarnewbies]

Re: Issues on cascading a Dc/Dc boost converter with an inve

Hi pauloynski

Thank you for the advice. Seem like you are the only one that reply to me. .

Would be very much appreciate if you can tell me more regards to the selection of inductor for my boost circuit.

My inductor is selected based on calculation (CCM) and simulation done using Psim software. The cascaded converters work well in Psim software.

The individual hardware implementation for both dc/dc converter and inverter are working well. I had tested their individual reliability.

The problem occur only when I cascaded them and vary the i/p voltage above 10V.

Rgds

 

[marthinus]

Re: Issues on cascading a Dc/Dc boost converter with an inve

At what voltage does the inverter start to work?When does the dc-dc start to regulate?

 

[FvM]

Of cause, inductor saturation is always an option. Without seeing waveforms and circuit details, it seems to me almost speculative to determine the actual problem.

In my opinion, there should be a understandable explanation. A few months should be sufficient to gather a bit more of information. For me it's usually the period covering circuit development, prototyping and pre-series production start.